Contamination of the environment by man-made substances has been considered a serious problem for a long time. Recently, concern about contamination of earth, air and groundwater by oil, toxic chemicals and other hazardous wastes has expanded beyond large-scale industry to encompass the activities of many small businesses such as automobile service stations, and many others. Both government regulations and social outcry have placed tremendous pressure on these businesses to avoid discharging hazardous wastes into the environment in the course of ordinary business activities.
For example, in a service station, washing or steam-cleaning an automobile engine or auto parts often causes engine oil, gasoline, and other chemicals to enter a storm drain system, or other waterways which can lead to contamination of earth or groundwater. However, until this disclosure, there has been no portable, self-contained way to conveniently and safely wash these objects and recover contaminants from them. Many other businesses and industries, large and small, have the same problems.
In addition, those who service remotely located equipment have a need to wash the equipment without discharging hazardous waste into the environment. For example, persons who service roof-mounted air conditioners containing lubricating petrochemicals, trapped pollutants or other chemicals are not permitted to wash the equipment in a manner that could cause chemicals to run off.
High pressure washing equipment is available, but in general, existing pressure washers have no containment capability for hazardous materials. They cannot prevent hazardous materials from entering the surrounding environment. Even if all the wash fluid is somehow recovered, hazardous wastes are not filtered out, so that these systems generate an enormous volume of wastewater which must be processed separately or placed in barrels for disposal.
Thus, there is a tremendous need now for a portable, zero-discharge wash apparatus which can recover oil, chemicals, and other hazardous materials from an object which is washed. In addition, there is a serious need for a wash apparatus which can recirculate and repeatedly filter the washing agent, producing a very small quantity of waste material, and for a wash apparatus which overcomes other disadvantages of the prior art, and provides other needed features.
Known pressure washing equipment has other serious disadvantages. For example, such pressure washers are ordinarily connected to a public water supply having unknown average pressure and unknown instantaneous pressure. Fluctuations in pressure of the public supply could cause damage to the pressure washer or render it usable to produce consistently high output pressure. In addition, even when the public supply has consistent pressure, its pressure may be outside an ideal operational range for the pressure washer. Thus, there is a need for a way to provide a controlled water supply to a pressure washer which is adjustable to enable an operator to achieve optimum performance of the washer.
In general, in one aspect, the invention provides apparatus for washing an object containing a contaminant and for recovering the contaminant, comprising: means for flowing a washing agent over the object; a tub mounted below the object for receiving the washing agent and the contaminant; means for circulating a slurry of the washing agent and the contaminant through at least one separator in the tub; means for filtering the contaminant from the slurry to produce a cleaned slurry flow; and means for recirculating the cleaned slurry flow into the tub.
Features of the invention include means for heating the washing agent; means for enclosing the object to prevent discharge of the contaminant into a surrounding environment; a pressure wash pump coupled to a water supply and to a pressure wash wand; a plurality of baffle walls arranged to divide the tub into a plurality of fluid containment chambers and a floor overlying the tub and having at least one channel for directing the washing agent and contaminant into the fluid containment chambers; a pump having an intake coupled to the tub and having an output coupled to at least one particulate filter; and a plurality of holes and channels interconnecting the fluid containment chambers.
Further features include a pressure wash pump having an intake and an output coupled to the tub, and a pneumatic valve for selectively coupling the intake of the pressure wash pump to the cleaned slurry flow and to a fresh water source.
In another aspect, the invention provides apparatus for washing an object containing a contaminant and for recovering the contaminant, comprising a tub mounted in an enclosure around the object and comprising a plurality of fluid containment compartments; a circulating pump having an intake coupled to a first compartment and having an output coupled to a second compartment; a contaminant separator in the tub having a separation intake coupled to a third compartment and having a separation output coupled to the first compartment; and a filter having a filter intake coupled to the clean water compartment and having a filter output coupled to the tub.
Some features of this aspect include: the tub is sealed to the enclosure; a pressurized source of fluid for washing the object is provided; and a source of air for drying the object is provided.
In a further aspect, the invention comprises apparatus for washing an object containing a contaminant and for recovering the contaminant, comprising a pressure washer for flowing a washing agent over the object; a tub mounted below the object comprising a plurality of baffles which divide the tub into a plurality of fluid containment compartments; a circulating pump having an intake coupled to a clean water compartment in the tub, and having an output indirectly coupled to one of the fluid containment compartments; a contaminant separator in the tub having a separation intake coupled to one of the fluid containment compartments and having a separation output coupled to the clean water compartment; and a filter having a filter intake coupled to the clean water compartment and having a filter output coupled to the tub.
In yet another aspect, the invention provides apparatus for optimizing performance of a fluid pump having a supply port and a pressurized output port, comprising a pressurized supply of a first fluid; a variable regulator coupled to the supply having a variable pressure output; and a second pump driven by the variable pressure output for impelling a second fluid into the supply port of the fluid pump. Some features of the invention are that the first fluid is a gas and the second fluid is a liquid; that the first fluid is air; that the second fluid is a washing agent; that the second fluid is water; that the fluid pump is an electric pressure washer; that the second pump is a air-driven water pump; and that an impeller in the second pump is a diaphragm.
In still another aspect, the invention provides a method for optimizing performance of a fluid pump having a supply port and a pressurized output port, comprising the steps of providing a pressurized supply of a first fluid; variably regulating the pressurized supply to produce a variable pressure output; driving a second pump by the variable pressure output; and using the second pump to impel a second fluid into the supply port of the fluid pump.